UC Merced Solar Cooling Demonstra4on Project

UCMercedSolarCoolingDemonstra4onProjectXCPCArrayDrivingDoubleEffectAbsorp4onChiller

XCPC-ExternalCompoundParabolicConcentrator§ A pair of trough parabolic reflector with evacuated tubereceiverthatconvertssolarradia7onintoheat.§ XCPCscanacceptincomingradia7onoverwideangleswithouttracking required. Also can collect diffused sunlight(cloudydays).Cxfrom1.15to1.55.§ ~50% thermal efficiency at 200°C.Rugged and tolerant todus7ng.Seasonal7ltadjustmentisnotrequired.

VaporAbsorp4onCoolingTechnologyThermallydrivencoolingcycle,Nomovingparts(Nocompressor). The refrigerant takes heat from thecooledspace,turnsintovapor,getsabsorbedintheabsorbentsalt.Thissolu7onagainheatedbytheheatsource(Solar)to separate each other, passed to condenser tocondensetherefrigerant&thiscyclerepeats.

TypicalPerformanceηcol~0.38

SolarCOP~0.4

DirtyPerformanceηcol~0.32

SolarCOP~0.33

CloudyPerformanceηcol~0.35

SolarCOP~0.36

YogeshBhusal,Benne.Widyolar,RolandWinston

SystemSchema4c&Specifica4ons

CollectorArray N-S E-W

ApertureArea 53.3m2 45m2

Inclina7onAngle 20 37

Concentra7on 1.15 1.4

#ofTroughs 160 60

Capacity@200oC 20kW 18kW

CoolingCapacity 6.6tons,23kW

CWStorage 500gallons

COP 1.1

BroadDoubleEffectLiBrAbsorp4onChiller§  DualFired(naturalgasbackup)§  LiBr(absorbant)+H20(refrigerant)pair§  Doubleeffect(2stage)requires140°C§  COP~1.1(coolingprovidedperheat)

This project has beenopera4ng for 6 yearsnow&coun4ng.Contact:ybhusal@ucmerced.edu

Recently, solar cooling has regainedthe research interest due todevelopment of solar collectors andthe availability of hot water drivenchi l lers which wel l match forsta7onary solar collectors withtemperature range 80-160oC. Tripleeffect chillers, which can poten7allyreach a COP of 1.7 with drivingtemperatures above 160 °C, are s7llunderdevelopment.